CDN problem? I have

CDN problem? I have one page on my site that is insecure. I've checked the plug ins and the error console and this is what I found (see screen shot attached). Am I right in thinking this has something to do with CDN that WPMUDEV uses? The code causing the issue is located here:

https://da8dsugrl65ch.cloudfront.net/www.greatannualsavings.com/0eb02999-4f0b-4678-a5b3-0cd38ea7e6d8.js:formatted

And this is the error it gives me:

0eb02999-4f0b-4678-a5b3-0cd38ea7e6d8.js:formatted:4132Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
send @ 0eb02999-4f0b-4678-a5b3-0cd38ea7e6d8.js:formatted:4132

And this is the specific piece of code causing that error:

if (a.open(t.type, t.url, t.async, t.username, t.password),